Telephone-exchange.



N0.v85 0,344. PATENTED APR.16, 1907.

Y E. E. CLEMENT. TELEPHONE EXCHANGE SYSTEM.

. APPLICATION FILED MAR. 20. 1905.

2 SHZEES-SHEET 1.

PATENTED APR. 16, 1907.

5. E. CLEMENT. TELEPHONE EXCHANGE SYSTEM-v APPLIOATION FILED MAR 20,1905.

2'SHEETSSHEET 2.

. have biit one 'signal' and that-is-not controlled' in any-way bycomplicated means,

" EDWARD or:wAsHmqToa-bismwi :QF m 1 'i pnmionmea amt 20,1905. seminal251,041.

To 'a/ZZ whoirt ittmalyeohc ern:

Beit known that I, EDWARD E. CLEMENT-5 a citizen of the United States,r'esidingyat. in the District of ,Columbim '5 have invented certain newand useful 'Im- Washington,

and reduce.

" ployed while increasing-their efiicieney;

: di'vi edjmultiplej system, in w such as polarized magnets-and thelike. ,The

"to main-switchboard -at" the. oentra'loffice. is a divided .into.- twoor more 'divisio'ns, {each f.

1; which' isa complete multiple board in itself with a' full complementof i -answering an multiple jacks for theline's-which are repreisentedin its extent. The =answering-jacks,

or shutters arejthe same in ordinary use and'needfi'iotfbe ofvanspecialitype. Infect my iinv'entionjis'f app cable-to any. type o 1 6'-switchboard and apparatus and to; any air- ,cuit. I have shownit-asapplied to- :1 Comv '1- mon-hattery-circnit having a two-wire cordandra three-wire} jack connection of the most a'dvajn'ced' type nowlmown in service; but it 3 5 'mayb'e applied 'gwith equal, facility toany;

type or any 'variety of system without sacr fice of its -essentialfeatures.

jacket some one division. Each't ,for-every one of its-multiple jacks asignal,

such as a lamp controlled by amagnet soeon- -nected that. the particularmagnet a'ndthe "5 particularlsi aldesired can be selected-bye subscriberw en calling. Each snbseribers line is of course represented on some oneof the divisions all itssections, but not on the, other divisions. Forcalls on that division cono nections are made direct; but for those onothers they aretrunked. -The method of this trunking the calls is of'the essence ofmy (invention; Eve 'call.;is;t'riin'.ked-;that is,

Specification of Letters Patent.

provements; Telephone-Exchange.'-- Sys 2 ftems', 10f which j thefollowing .isgai 'specific a-'-- f tion; reference fbeing had therein tothe ac a y n f rew s 'w r fro-- 'nvent1o11 relates to telephone systems;

andhas for its object to siinp v the expense oflar e' systems,especiallythose; ei-switchhoards' are em-- mean oneinterconnectingcenter within four-'- v to walls,'but :anyeorrel'ated' group; ofcenter-sf. Between the "divisions of the; main board trunk-linesextend.Each trunkis multipled 40 to all the divisions and has'a terminalplu%o"rl as 0 orders. r

trunked, as herein s t forth, with manifest advantape and with the sameease'and oer-1 f thelin'e ack-witliont' any a 1 Patentedpril rs, 190?."

predetermined selective signal then deter:

mines.whether the trunk-signal shall be displayed at the, home divisionor some other ,division and at which. The trunk-si als 6p are treated'by the operators as the ca ing- Signals-of subscribersto be answered-andthe r attended to; and hence after inserting a8 a trunk jack m responseto acall-11f,

a connection. .therew1 th the operator '6 the jackof-t e wantedlineandto complete the connection. This she cando,"for the call has come tothe division where the wanted subscriber-has a connection in a -multiple7o" jack for each section therein. V v At-the subseribersstation'ithevapparatus is ve simple. I have shown itras" apair ofpushuttons'witha reta' -magnet'which when a button is; depre'ssed' oldsit in' and 75 the otherbuttonbut' until thecall'is finally I extendedtotheoperaterre' aired and there answered. v The 1 special ca ling?apparatus 7 and 'push-buttons are then out out auto? -mati'cally','sothat nothing remains in the cir- 3o cuit except the .ordinarycominonbattery j lineT-relays, .f or annuneiators, "and line lamps telephone.By means .whioh- -I "shallllnot specifieally' claim herein ,the number'of di give alfilll' size" tone hundred thousand sob-.

very s lar stvaexc ange new fin-o eration."" o.. By fiififi angefhi'swqnnet'ion do. notfl which together {interchange business. and" 1-thereby combine toserve alispecifiedxgroup -of subscribers; under one,:GOnbIf Ol. Thus there maybe ten exchangesin the narrowei' it sense,constitutingten divisions. according to 1 niy present invention,scattered through ferent parts of acity, but all commonly cone io'otrolled and working underthe same rules and In such case thfcal-ls maybe i tainty 0 operation as if the divisions. we

under one roof, and thebo'ardsside by side."

If the exchanges individually be v widely;

separated-say more than twentyvehn n dred feet apart-a combination of;

wires may be required tosave the three-wife Q extensions, only as manytriplets. beiag' fi .a latch controlled. by a magnet D use at once,allowing for peak hours and for spares. This, however, 'as well as theother problems I have mentioned above, need not be discussed at lengthherein, as they will be fully treated in other specifica- My present ivention is illustrated as to one embodiment inthe accompanying drawings,wherein-- Figure is a diagram showing a subscribers station connected toone division of a divided multiple switchboard, and the trunkterminalcircuits tlicreat, as well as atrunk extension to another division. Pig.2 a similar and synnnetrical diagram made as a continuation of thefirst, showing the operators" cord-circuits and a second subscribersline and station outfit, these appertaining to a second division of themritchboard.

Referring to the drawings, A, in Fig. 1, and A, in l ig, 2, aresubscribers stations, each provided with the usual talking set of acommon battery system and each provided, also, with selective mechanismby which the divisions of the exchange may be. di'll'crentiat-ed. As allthis at each station is the same I shall describe that at station Aalone.

At station A, 'l is the transmitter, .lt the receiver, ll. the switchhook, C the condenser, Q theringcr, all of usual or any desired type.

I) and i) re two push-buttons, (shown of insulating material as to headsand shanks) although the latter may obviously be of metal and inpractice would be so. Each button has contact-spring (Z or cl, normallyback on a lixed contact, these two lixed contacts being in the'circiut34 35 ot the talking set, so that when either button is pressed thetalking-circuit is broken. I have not chosen to complicate this diagramby showing anything but the essentials; but in practice I may, andprel'erably will, make a nun'iber of changes entirely within the scopeof my invention, which will do awaywith the disagreeable click in therecci-verll Each button when pushed iuis adapted tobe held in by For thebutton Dthis latch is-shown as a toe on the. end of the armature-leverd", and for the button D it is shown as a similar toe 0d the ar Botharmatures are conand of course llach latch holds its button when pushedin. and also prevents itsdieing so pushed in if the armature is upbefore the pushing 1s cssayed.

This prevents tan'iqrering with the signal al'tcr it is set. Iheu thebutton l)is pressed, it grounds the side 2 of line through the u'iaguctxl)", and when the button I): is pushed it similarly grounds the side 1offline through the same magnet, each, as l have stated, orcmng thetalking-circuit and leaving the other side oi line ungrounded, At thecon battery B.

tral-otl'ice'eiitl of the line itpasses to the contact-terminals m and m(:l' the cut-oil relay .M. Thencenormally bothsidesollinepass to themagnet ll of the limva'clay, controlling the signal min the localcircuit (5 5 3 from Hence no matter which side of line is grotu'ided atthe subsrationthe linerelay I will get: current through the relay 1)"and line.

Each line has a terminal answering-jack J and nuzltiple jacks .l. l): :hjack has the line-terminal springs j j and a thimble j". The thin'iblesare all connected togcthm' by wire it) and through wire 7 tothc c.t-ollrelay M and ground. 'lo cooperate with the line-jacks, I preferablyprovide only the trunk-plugs P for answering pvrposes, and in practiceit is desirable to have the answeringjacks J and the trsnk-plv s lbclore one set of operators, whose sole daty is to stick plc'gs andwithdraw them according to thc s' uals, the,tranlejacks J" J and thecoL'af- (wits (shown in Fig. 2) being before another set of operators,who correspond to the present subscribers operators. The pl g l" has atip, ring, and sleeve 7) p 1) the tip and ring forming tern'iinals ofthe main track-wires 11 12 and the sleeve the terminal oi'thc relaywire13 passing to relay L and batter The wires 11 1.2 have extensioas Hi 17passing to both divisions of the switchboard, (which in this case issupposed to be a twodivision' board.) At each division these trunk-wiresterminate .in an answering-jack J or J, having springs similar to thoseof the line-jacks, and thimbles j connected together by wire 15 andthence by a branch to to the trunk .eut-ofl relay M and battery. Therelay L 'controls, through its arn'iat'ure m, the circuit 14 m of thelamp m which iS' atonce the supervisoryand clearingout signal of thetrunk. The ainiatnre m" is controlled by the trunk ci;tofl'relayi\lwhose other contacts m m? control the tir iitsof the trunk signal-relaysL U. ()l these the former is connected from the tri nk-wire 16 throughthe cut-ofl' contacts on to the battery by wire 16 and the latter, If,is similarly. connected from the wire 17 thro gh the eut-oll' Contact-Imi t0 the wire lti and battory "lhe grounding of either side of the linewill therefore energize one of these relays. For a purpose presently tobe rci'crred to the wires 16 and 17 are reverse-'1 bctweerrthe jacks .l"J" and toone side oi the oi'incctions of the relays l/ lfiinthiscase onthe side toward the jack J. Cooperating with this trcnk-circi'it andwith the 'line-circ'l it dcscribcd I may employ the cord-circuit shownin Fig.2. llere the pl'z l l are connected by the cord epnditctors Z1 222" 24, condl'ctively separated by the condensers C (1 Upon each side ofthe condensers a bridge is l'orn'ed'across the cord inch ding thebattery B, this being shown, in the one case, at 25 26 and in the otherat 27 inserts a plug P, whereupon ing of this lamp would mean probabletrouble with the trunk, and another trunk would be substituted promptlytherefor.

Detaileddescription of the operation of the parts iirl ig. 2 is thoughtto be unnecessary, so lv will merely refer to the reason for reversingthe conductors 1.6 17 on jack J. It will be observed that the batteryB,.in accordance with standard. practice, has its positive terminalgrounded. if both trunk-jackswere. directly connected to line, thiswould bring the ground on one side or the other, accord ing to the jackselected. ill" the cord-circuits are uniformly connected tobattery--that is,

28, the bridge containing the su ervisory relay S and the chokecoil Si,wiiile the second contains similar pieces of apparatus S S. Thesupervisory relays, respectively, control the two supervisory lamps s 3,whose circuits, open when the plugs are idle, are closed in use by there laysL L connected to the sleeves of the respective plugs.

"he operation 01? my invention thus described is as follows: SubscriberA ,desiring to converse with subscriber A, ascertains that the number ofthe latter is such that he isv in a dili'erent division 'lTOlil hiscaller. ll"

we assume A to be in the A division and A to with the sleeve side alwaysto the live side oi be in the B division, (which may be the battery fortest purposesthe result would be. marks on the buttons,) the callerwould then that the two grounds, one at central and the press his Bbutton. in doing so he closes the other at the substation, would bothcome onv the same sideof line. for one jack J, but would come onopposite sides of thcline and battery for the other jack J. The resultol" this would be. that for all connections on jack J the relay 1)" atlet go. ,llence I. simply reverse the conductors 16 17, as shown, andthus bring the two grounds always on ti o same side of battery alter theoperators ilug l. is in any trunkfollowing circuit: ground, relayl),contact d 11, 33, 11, 5, 3, 19, B. Both the linc-relay andthe relay I)pull up, the button 1) (which we have called the B button) is retainedin its depressed position, and the lever d is drawn up behind the otherbutton to prevent its being de )ressed. The operator in Fig. 1,perceiving t ie line-lamp m to light, circuit through the cut-off relayis formed as follows: ground jack. The test of course unnecessary to torelay M, 7, 1 p, 13, L, It), B. Thecutconsider, the trunk-jacks are onlyanswering-jacks. It would be all right, however, in any case, providedthe relay M were grounded instead of to battery and the relay ll tobattery instead of grounded. This is a mere reversal of connections,which is always understood. where necessary;

It will be apparent that while I. have thus described a two-buttonsubstation and a twodivision switchboard the same may be made four oreight or sixteen by any suitable method, and. 1 contemplate all suchchanges as within the scope ol" the appended claims.

1 am aware that sundry changes may be made in the apparatus ancircuits 1. have described without departing from the spirit of myinvention, and IV wish it distinctly understood that all such chan esare well within the scope and purview a l my claims.

feature of my present inventrunk-lines between oil relay then acts, andat the same time the potential of the test rings or thiinbles 7' israised for test purposes. The eut-oll' relay draws in its armatureconnections so that they make contact with. the terminals of wires 8 and.1 before they break with the terniinals leading to the relay 1.1. Thereason for this is that there must be no break in the llow ofbattery-current to line until the answering operator finally makesconnection. The line-circuit 1 2 is now continued through the trunkwires 16 17 to the multiple 'acks J J in the two divisions ol the board.The ground remaining on the wire 1 at the subscribers station, currentilows'through the relay 1. by the following pathz'ground at thesubstation to relay I), contact (i d, 33, 1,111., 8,'j,p, 11, m, L, 16,19,13. The relay ll therefore pulls up and lightsv the lamp 171. at theB board. The operator at that board, using the cord-circuit shown inFig. 2, answers the cal-l and handles the connection exactly the same asit she were dealing with the subscribers line direct. As soon as sheinserts the plug P, however, in the jack J she closes circuit throughthe trunk cut-ofl' relay M. fby the following path: ground to relay L,p, iyof jack J", 15, 16, M, 1.6, 19, B. This relay then pulls up, wellas the relay L", the lamp-relays i L", which were previously bridgedacross the trunk, being thereby removedand the lamp darkened. At thesame time the lamp m, which lighted when the plug 1. was iirstinserted,is put out,

The essential tion is the provision of changes, the trunk-linescontaining selective apparatus by which the subscriber may dif'ferentiate, soas to select the particular exchange or division of theswitchboard upon which his wanted corres ondent' has .a'terminal and canbe reache My. invention has beeiidescribed as applied to mai iialmultiple switchboards only; but it may obviously be applied toautoma'tic or semi automaticsystems and to transfer-boards as well andwithout change in essence. Such applicationl consider .within' the skillof any telephone-engineer well in- .whicniiulicates to the {last 0)erator that the formed in his profession. y y call is being attendedto. ontinued burn- Having thus fully described my invention,

the substation would never aparate multiple boards or separate exwhat Iclaim, and desire to secure by Letters Patent, 15

1. In a telephone-exchange system, aplu-- tribu ted upon differentportions ol its division,

trunk-lines containing selective apparatus extending unbroken betweensaid (llVlSlOIlS,

boards, or exchanges and means by which a subscriber may affect saidselective apparatus and dil'lerentiate so to manifest a particulartrunk-signal at the particular division upon which a terminal of theline wanted is to be found and no other, substantially as de scribed.

2. In a telephone-exchange system, a subscribe'rs line, a controlling.lay, means at the substation for grounding one side or the 1 other ofthe line tln'ough the controlling-relay, a line-signal at the centraloffice displayed in response to the subscribers act in .lcalling, atrunk-line extending to multiple terminals at a plurality of switchboarddivisions or exchanges, selective relays connected to said trunk-line,means .to supply current thereto and to the line, and signals todesignate a particular division or exchange wanted,controlled by saidrelays, and responsive to the grounding of a snbscribors line,substantially as described.

3. In a telephone-exchange system, a plu rality of subscribers lines, acentral ol'lice, a plurality of centraboilice switchboards eachcontaii'iing answeringterminals and multiple terminals for a particulargroup of said lines, a telephone set at a subscribensstation and asignaling set thereat comprising a circuitcloser and aretaining-magnettherefor, a linesignal device normally connected to the line at centraland associated with the answeringterniinal thereof, together withtrunkdines extending between the switchboards, and each provided with aconnective terminal upon each board, signals associated with the saidtrunk-line terminals, one for each, and circuit-closing devices for saidsignals normally connected to the trunk to be affected by thesubscribeis circuit-closing device so as to display. the particularsignal desired upon a particular board of the set, containing one ormore multiple terminals of the line;

wanted, substantially as described.

4. in a telephone-exchange system, a central service-bureau divided intoa plurality of switchboards or exchanges, subscribers lines.

4 each terminating at one division only; trunklines less in number thanthe i'iuniber of sub scribei's l nes and extending between the severalexchanges or divisions, each trunlehne having connective terminals attwo or more or said exchanges or div1sions;a plurality'of eachtrunk-line, with means to supply current thereto and to the lines, andsignals associated said relays; together with circrut-controllingdevices at each subscribens station arranged to cooperate with andalfect said relays; whereby a subscriber. may signal his own divisionfor aconnection, and being trunked imay selectively signal an operatorat the division or exchange in which a line wanted is terminated,substantiallyas described.

5. In a telephone-exchange system, a divided switchboard and subscriberslines each posed of two wires both normally connected to aline-annunciator at the terminal division; a'pair of circuit-closers anda locking magnet therefor at the subscribersstation, whereby one side orthe other of the line may be held groundedat will and the line-signalthereby set; a trunleline between the divisions having two wires eachconnected to a generator and ground through suitable relays,trunk-terminal signals at the different divisions controlled by saidrelays; and operators connective circuits in each division; the whole soarranged that when a calling subscriber is trunked his line-signal isdisabled and the trunk-relays brought under the control of the line toset one of the trunk-signals at the predetermined division; and meanswhereby an operator at the desired division may eomplet-e the connectionbetween the trunk-terminal and the line of the wanted subscriber, and inso doing may disable the trunk-signals, and in finally brcakii'ig theconnection may actuate a trunk disconnect signal at thecalling-subseribei"s division, substantially as described.

6. In a telephone-exchange system, a plurality'oi subscribers stations,a central station, and a plurality of switchboard devices eachcontainingterminals for a particular group of the subscribers lines, aplurality of trunk-lines extending between the switch.- board divisions,a common battery supplying current'for the lines and trunks, a pluralityof terminals and associated signals for the trunks, the same beingdistributed on the several boards or divisions, and a controllingmagnetfor each signal connected between, the battery and one or the other sideof the trunk, together with means at a subscribe'rs station fordetermining the flow of current from said battery throughone' or theother side of the trunk, and thecorresponding signal controlling magnet,substantially as described.

7. In a telephone-exchange system a plurality of subscribers lines andstations, a plurality of central-otfice switchboards with.

answering and multiple terminals upon each selective relays connected toopposite sides'of with the 'trunl -terminals and controlled byterminating in one division, each line com board for a articular groupof subscribers a tru -signal associated with each terminal,

and a controllingmagnet therefor, a plurality of separate circuitscomposed in part of the members of the trunk, and means at a subscribersstation to complete one or another of said circuits, at will, so as todisplay a desired signal,substantially as described.

8.,111 a telephone-exchange system, a sub- 1 scribers station havingselective devices, and

a'central switchboard divided into distinct parts, together withtrunk-lines normally extending'unbirolien to all the parts, and meanswhereby the subscriber 'may set a signal therethrough on any division ofthe switchboard, substantially as described.

9. In a telephone-exchange system, a subscribers line, a talking settherefor at the subscribers station, and a signaling set comprising acircuit-closer and a retaining-magnet the'r'efor, a line-signal devicenormall connected to the line at central, and a ternnfinal connectivedovice,together with a trunkline extending iinb'roken to more than onedivision of the exchange or system, and pro- I vided with a connectiveterminal at each,

signals associatedwith said trunk-line, one

; for each terminal, and circnit closing devices for saidsignalsnormallyconnected to the trunk to be effected by the subscriberscircuit-closing device so as to close the circuit of any particularsignal desired, so as to selects particular division of the switchboard,snbstantially as described.

10. In a teleplioneexchange system. a plu-- rality of subscribers linesand a plurality of central ofiice switchboard divisions, withline-circuits extending from the subscribers stations to the saidswitcllboards, each line terminating upon less than the full number ofboards, a number of line extensions or trunlv lines passing unbrokenbetween the several switchboards, each having multiple terminals on thesaid boards and signals associated therewith, all of said trunks beingn01.-- mally disconnected from the lines, a calling signal for eachline, and means for connecting a line when calling to an extensionontrunlt,

together with means at the subscribers sta tion for actuating one or theother "of the signals associated with said trunk, according to theparticular boardupon which the line of the Wanted subscriber terminates,sub: stantially as described. i

in testimony whereof I have aflixed m y signatsre in presence of twoWitnesses.

v EDWARD CLEMENT.

iillitriesses:

H. M. STERLING,

G. M. QOPENHAVEN

